1. Field of the Invention
This invention relates generally to the manipulation of optical wavefronts. More particularly, this invention relates to optically relaying an optical wavefront in pieces.
2. Description of the Related Art
Wavefront manipulation is a basic function in optics. Many conventional optical elements are designed to manipulate optical wavefronts in different ways. For example, lenses focus/defocus wavefronts and can introduce or remove higher order perturbations in the wavefront (e.g., aberrations), mirrors reflect wavefronts, prisms change the direction of propagation of wavefronts, and devices such as beam splitters and dichroic elements can be used to multiplex/demultiplex wavefronts. Imaging is a basic optical function that depends heavily on wavefront manipulation. An imaging system receives an incoming optical wavefront and largely converts phase variations in the wavefront to intensity variations that are similar to the original source producing the wavefront (i.e., similar to the object).
However, wavefront manipulation usually requires space, as it is the propagation of the manipulated wavefront over space that typically results in the intended effect. For example, for a 50 mm diameter, F/1 imaging system, the image is not visible immediately after the imaging lens. Rather, the wavefront must propagate over the focal length (or on the order of about 50 mm) in order to form the image. As a result, the imaging system typically is more than 50 mm thick.
Thus, there is a need for devices that can manipulate and/or relay optical wavefronts but in a more compact manner. For example, it would be desirable to design a 50 mm diameter, F/1 imaging system that was significantly thinner than 50 mm.